MongoDB - এমবেডেড নথি জিজ্ঞাসা করবেন?

MongoDB-তে এমবেডেড নথিগুলি জিজ্ঞাসা করতে, aggregate() ব্যবহার করুন। আসুন নথি-

> db.demo705.insertOne(
...    {
...       _id:101,
...       "Information":
...       [
...          {
...             "StudentName":"Chris",
...             "StudentAge":21
...          },
...          {
...             "StudentName":"David",
...             "StudentAge":23
...          },
...          {
...             "StudentName":"Bob",
...             "StudentAge":20
...          }
...       ]
...    }
... );
{ "acknowledged" : true, "insertedId" : 101 }

Find() পদ্ধতি -

> db.demo705.find();

এটি নিম্নলিখিত আউটপুট −

{ "_id" : 101, "Information" : [ { "StudentName" : "Chris", "StudentAge" : 21 }, { "StudentName" : "David", "StudentAge" : 23 }, { "StudentName" : "Bob", "StudentAge" : 20 } ] }

MongoDB −

> db.demo705.aggregate(
...    { $unwind: '$Information' },
...    { $match: {'Information.StudentAge': {$gte: 21}}},
...    { $project: {Information: 1}}
... )

এটি নিম্নলিখিত আউটপুট −

{ "_id" : 101, "Information" : { "StudentName" : "Chris", "StudentAge" : 21 } }
{ "_id" : 101, "Information" : { "StudentName" : "David", "StudentAge" : 23 } }